EPA.94b.lead.df.RdLead concentrations (mg/Kg) in soil samples at a reference area and a
cleanup area. Nondetects reported as <39. There are 14 observations
for each area.
EPA.94b.lead.dfA data frame with 28 observations on the following 4 variables.
Lead.origa character vector of original lead concentrations (mg/Kg)
Leada numeric vector of lead concentrations with <39 coded as 39
Censoreda logical vector indicating which observations are censored
Areaa factor indicating the area (cleanup vs. reference)
USEPA. (1994b). Statistical Methods for Evaluating the Attainment of Cleanup Standards, Volume 3: Reference-Based Standards for Soils and Solid Media. EPA/230-R-94-004. Office of Policy, Planning, and Evaluation, U.S. Environmental Protection Agency, Washington, D.C. pp.6.20–6.21.